[Influence of cadmium on structure and functions of mitochondria in hepatic cells].
OBJECTIVE
To study the effects of cadmium on the structure and functions of mitochondria in hepatocytes.


METHODS
Mitochondria were isolated from cultured human hepatocytes of the line WRL-68 and co-cultured with cadmium chloride (CdCl2) of the concentration of 1, 5, and 10 micromol/L, and WRL-68 cells not treated with CdCl2 (0 micromol/L) was used as control group. Cyclosporin A (CsA) was added into the culture medium. Mitochondrial permeability transition pore (MPTP) opening degree was tested by spectrophotometer. Morphologic changes of mitochondria were observed under transmission electron microscope. The activities of Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, LDH, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the contents of malondialdehyde (MDA) were measured Mitochondria membrane potential (MMP) was monitored by spectrofluorimeter with fluorescence dye Rh-123.


RESULTS
CdCl2 reduced the absorbance of mitochondria, signifying the opening of MPTP, concentration-dependently. The absorbance of mitochondria co-cultured with CsA and CdCl2 10 micromol/L was higher than that of the. CdCl2, 10 micromol/L group. Mild swelling was seen in the mitochondria treated with CdCl2. The MMP values of the CdCl2 5 and 10 micromol/L groups were significantly lower than that of the control group (P < 0.05, P < 0.01). The activity levels of ATPase, LDH, SOD, and GSH-Px in mitochondria decreased in the CdCl2 groups (all P < 0.05), and the contents of MDA increased in the CdCl2 groups compared with the control group.


CONCLUSIONS
CdCl2 causes destruction of mitochondria structure, opening of MPTP, decrease of MMP, and changes of vitality of mitochondria enzymes that all play important roles in apoptosis of hepatocytes.
Zhang
Na-na
NN
College of Life Science, Nanjing Normal University, Molecule and Medicine Biotechnology Lab of Jiangsu Province, Nanjing, China.
Mao
Wei-ping
WP
Wei
Chuan-jing
CJ
Zhou
Lei
L
Liu
Hong-yun
HY
Feng
Juan
J
D000251:Adenosine Triphosphatases / Q000378:metabolism; D019256:Cadmium Chloride / Q000494:pharmacology*; D002460:Cell Line; D005979:Glutathione Peroxidase / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008315:Malondialdehyde / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008854:Microscopy, Electron; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D013482:Superoxide Dismutase / Q000378:metabolism
D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000251:Adenosine Triphosphatases; D019256:Cadmium Chloride